title: Human chorionic gonadotropin and alpha-fetoprotein concentrations in pregnancy and maternal risk of breast cancer: a nested case-control study.
abstract: Pregnancy hormones are believed to be involved in the protection against breast cancer conferred by pregnancy. The authors explored the association of maternal breast cancer with human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP). In 2001, a case-control study was nested within the Northern Sweden Maternity Cohort, an ongoing study in which blood samples have been collected from first-trimester pregnant women since 1975. Cases (n = 210) and controls (n = 357) were matched for age, parity, and date of blood donation. Concentrations of hCG and AFP were measured by immunoassay. No overall significant association of breast cancer with either hCG or AFP was observed. However, women with hCG levels in the top tertile tended to be at lower risk of breast cancer than women with hCG levels in the lowest tertile in the whole study population and in subgroups of age at sampling, parity, and age at cancer diagnosis. A borderline-significant decrease in risk with high hCG levels was observed in women who developed breast cancer after the median lag time to cancer diagnosis (> or =14 years; odds ratio = 0.53, 95% confidence interval: 0.27, 1.03; P = 0.06). These findings, though very preliminary, are consistent with a possible long-term protective association of breast cancer risk with elevated levels of circulating hCG in the early stages of pregnancy.
authors.affiliation: Division of Cancer Epidemiology, German Cancer Research Center, In Neuenheimer Feld 280, Heidelberg 69120, Germany. a.lukanova@dkfz.de
authors.forename: Annekatrin
authors.initials: A
authors.lastname: Lukanova
authors.forename: Ritu
authors.initials: R
authors.lastname: Andersson
authors.forename: Marianne
authors.initials: M
authors.lastname: Wulff
authors.forename: Anne
authors.initials: A
authors.lastname: Zeleniuch-Jacquotte
authors.forename: Kjell
authors.initials: K
authors.lastname: Grankvist
authors.forename: Laure
authors.initials: L
authors.lastname: Dossus
authors.forename: Yelena
authors.initials: Y
authors.lastname: Afanasyeva
authors.forename: Robert
authors.initials: R
authors.lastname: Johansson
authors.forename: Alan A
authors.initials: AA
authors.lastname: Arslan
authors.forename: Per
authors.initials: P
authors.lastname: Lenner
authors.forename: Göran
authors.initials: G
authors.lastname: Wadell
authors.forename: Göran
authors.initials: G
authors.lastname: Hallmans
authors.forename: Paolo
authors.initials: P
authors.lastname: Toniolo
authors.forename: Eva
authors.initials: E
authors.lastname: Lundin
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001943:Breast Neoplasms / Q000097:blood* / Q000453:epidemiology*; D016022:Case-Control Studies; D006063:Chorionic Gonadotropin / Q000097:blood*; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D007118:Immunoassay; D008875:Middle Aged; D016017:Odds Ratio; D011247:Pregnancy; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult; D000509:alpha-Fetoproteins / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins